The present invention relates to a steel composition and particularly relates to a steel composition for a housing of an inflator for inflating an inflatable vehicle occupant protection device.
An inflator for inflating an inflatable vehicle occupant protection device includes a quantity of a stored gas and a body of combustible material stored in an inflator housing. An igniter is actuatable to ignite the body of combustible material. As the body of combustible material burns, the combustion products heat the stored gas. The heated stored gas and the combustion products form an inflation fluid for inflating the vehicle occupant protection device. Another inflator includes a stored inert gas and a stored combustible gas, such as hydrogen. An igniter ignites the combustible gas, which heats the stored inert gas.
The present invention is a low carbon high strength steel consisting essentially of, by weight, about 0.07% to about 0.12% carbon, about 0.70% to about 1.60% manganese, up to about 0.020% phosphorous, up to about 0.015% sulfur, about 0.06% to about 0.35% silicon, about 0.25% to about 1.20% chromium, up to about 0.65% nickel, about 0.20% to about 0.70% molybdenum, up to about 0.35% copper, about 0.02% to about 0.06% aluminum, up to about 0.05% vanadium, up to about 0.25% residual elements, and the balance iron.
Preferably, the present invention is an inflator for inflating a vehicle occupant protection device. The inflator comprises a housing and a supply of gas stored in the housing. At least a portion of the housing consists essentially of, by weight, about 0.07% to about 0.12% carbon, about 0.70% to about 1.60% manganese, up to about 0.020% phosphorous, up to about 0.015% sulfur, about 0.06% to about 0.35% silicon, about 0.25% to about 1.20% chromium, up to about 0.65% nickel, about 0.20% to about 0.70% molybdenum, up to about 0.35% copper, about 0.02% to about 0.06% aluminum, up to about 0.05% vanadium, up to about 0.25% residual elements, and the balance iron.